Traveling in any capacity poses several risks, be sure to be prepared to treat a reaction immediately.

Traveling with a Food Allergy Links:

Select Wisely
Medicine.Net
Food Allergy.org
Allergic Child.com
Hotel Fun 4 Kids.com
Anaphylaxis Canada

Air Travel:

Some Airlines serve peanuts as their in-flight snack, this is obviously is a great threat to anyone with a peanut allergy. Most of these airlines provide a "buffer" zone (typically 3 rows) between you and the passengers being served peanut snacks.

Buffer or not, it is still possible to have a reaction while on the flight because of the airborne particles or because of the peanut protein left everywhere by hands that have touched peanuts. The potential for a reaction on a peanut-filled flight is great, it could happen from accidental ingestion, skin contact or inhalation.

A reaction from airborne particles will not be as severe of a reaction as if you had actually ingested the peanuts. It would be very hard to avoid a reaction of any type while traveling on an airplane that has peanuts served on it several times a day. If at all possible, phone the airlines prior to booking your trip and choose a carrier that does not serve peanuts during the flight. Many airlines are now serving pretzels and cookies as an alternative to peanuts.

For more info on travelling, see the Peanut Allergy Handbook.